Transition from 1 cell to multi-cellular organism

Fertilization  Sperm & egg join to form zygote Cleavage  rapid cell division : Fertilization  Sperm & egg join to form zygote Cleavage  rapid cell division Morula: 16 cells Blastula: 128 cells

 Differentiation  transition from general to specialized  Totipotent ▪ Ability to form all cell/tissue types ▪ Ex: zygote  Pluripotent ▪ Ability to form many cell types ▪ Stem cells ▪ blastula

 Gastrula  3 layered embryo  Ectoderm: ▪ Outer layer ▪ Skin, nervous system, outer openings  Endoderm: ▪ Inner layer ▪ Organs (lungs, digestive tract, etc.)  Mesoderm ▪ Middle layer ▪ Muscles, bone, blood, fat

 Epithelial  Inner/outer lining  Regulation  Connective  Between other tissues  Support & structure  Muscle  On bones & w/in organs  Movement  Nervous  Thru-out body  Respond to stimuli

 Classification  # of cells ▪ Simple (1 layer) ▪ Stratified (>1 layer) ▪ Psuedostratified  Shape ▪ Cuboidal (square) ▪ Columnar (rectangular) ▪ Squamous (flat tiles)

 Classification  types of fibers  Dense (collagenous) ▪ Strong durable  Elastic ▪ Flexible, stretch  Loose (reticular) ▪ Thin, branched

 Types  Areolar (surround organs)  Adipose (protect)  Fibrous ▪ Tendons (M  B) ▪ Ligaments (B  B)  Cartilage  Bone  Blood

 Classification  Striations (stripes)  Voluntary/Involuntary  Types  Skeletal ▪ Striated ▪ Voluntary ▪ Found on bones

 Cardiac ▪ Striated ▪ Involuntary ▪ Heart  Smooth ▪ No striations ▪ Involuntary ▪ Lines organs

 Transmit electrical impulses  Dendrite  Conduct electrochemical signals w/in nervous system  Axon  Transmission of signals from nervous to other tissues

 Built from 2/more types of tissues